Background: Historically, acute appendicitis requires surgical treatment. In recent years, there has been an increased interest in treating uncomplicated cases in a conservative way. The development in radiological and laboratory diagnosis has allowed for better possibilities of identification and watchful waiting of simple appendicitis. Objectives: The aim of the study was a retrospective evaluation of the efficacy of conservative treatment of uncomplicated acute appendicitis in children diagnosed based on clinical, laboratory and sonographic signs. Materials and methods: The diagnosis of uncomplicated acute appendicitis was based on the clinical signs, laboratory tests and ultrasound findings. Two clinical criteria, one laboratory criterion and two sonographic criteria, were assumed as a clear diagnosis of appendicitis. the retrospective assessment was conducted among 382 children who were hospitalised for suspected appendicitis. In those we identified a group of 66 children who met the criteria of acute appendicitis. The efficacy of conservative treatment in patients who met the criteria mentioned above was evaluated. Results: Within the period of at least one year, 89.4% of patients (59/66) were not re-hospitalised for recurrent symptoms. Eventually, 92.4% of patients (61/66) included in the study did not require surgical treatment. Conclusion: Uncomplicated acute appendicitis should be initially treated conservatively with watchful waiting. The vast majority of uncomplicated appendicitis cases can resolve spontaneously.